Emailing invoices to Local Email Works, but the same invoices to External Email Does Not Work.
Seems that this issue started this month, January 2022. For December 2021 and before, the invoices that were manually created and via Recurring Invoices were emailed to external addresses just fine. For many months prior, Recurring Invoices emailed properly to local and external email addresses.
We continue receive the CC’d notifications that the invoices have been emailed properly as have always. Now, if an invoice is sent to an internal email it goes fine but to an external email, it appears to go but actually does not. We can send email directly and successfully to the external email using webmail and an email client such as Thunderbird using the same mail server as configured with Invoice Ninja. So, email is actually reaching the external email addresses fine except through Invoice Ninja.
We’ve updated Invoice Ninja to 4.5.47 on a production and test installation and the issue persists. Our PHP version has remained 7.3 during this entire time frame. Using the same hosting server but on a different Invoice Ninja install, we get the same results. Sending messages from the same host server as the Invoice Ninja installation reaches external email addresses successfully. Any advice to help identify the issue?